Running examples in 'ssc-Ex.R' failed
The error most likely occurred in:

> ### Name: coBC
> ### Title: CoBC method
> ### Aliases: coBC
> 
> ### ** Examples
> 
> 
> library(ssc)
> 
> ## Load Wine data set
> data(wine)
> 
> cls <- which(colnames(wine) == "Wine")
> x <- wine[, -cls] # instances without classes
> y <- wine[, cls] # the classes
> x <- scale(x) # scale the attributes
> 
> ## Prepare data
> set.seed(20)
> # Use 50% of instances for training
> tra.idx <- sample(x = length(y), size = ceiling(length(y) * 0.5))
> xtrain <- x[tra.idx,] # training instances
> ytrain <- y[tra.idx]  # classes of training instances
> # Use 70% of train instances as unlabeled set
> tra.na.idx <- sample(x = length(tra.idx), size = ceiling(length(tra.idx) * 0.7))
> ytrain[tra.na.idx] <- NA # remove class information of unlabeled instances
> 
> # Use the other 50% of instances for inductive testing
> tst.idx <- setdiff(1:length(y), tra.idx)
> xitest <- x[tst.idx,] # testing instances
> yitest <- y[tst.idx] # classes of testing instances
> 
> ## Example: Training from a set of instances with 1-NN as base classifier.
> set.seed(1)
> m1 <- coBC(x = xtrain, y = ytrain, 
+            learner = caret::knn3, 
+            learner.pars = list(k = 1),
+            pred = "predict")
Error in namespaceExport(ns, exports) : 
  undefined exports: %s!=%, %s!==%, %s+%, %s<%, %s<=%, %s==%, %s===%, %s>%, %s>=%, %stri!=%, %stri!==%, %stri+%, %stri<%, %stri<=%, %stri==%, %stri===%, %stri>%, %stri>=%, stri_datetime_add<-, stri_sub<-, stri_subset<-, stri_subset_charclass<-, stri_subset_coll<-, stri_subset_fixed<-, stri_subset_regex<-, stri_c, stri_c_list, stri_cmp, stri_cmp_eq, stri_cmp_equiv, stri_cmp_ge, stri_cmp_gt, stri_cmp_le, stri_cmp_lt, stri_cmp_neq, stri_cmp_nequiv, stri_compare, stri_conv, stri_count, stri_count_boundaries, stri_count_charclass, stri_count_coll, stri_count_fixed, stri_count_regex, stri_count_words, stri_datetime_add, stri_datetime_create, stri_datetime_fields, stri_datetime_format, stri_datetime_fstr, stri_datetime_now, stri_datetime_parse, stri_datetime_symbols, stri_detect, stri_detect_charclass, stri_detect_coll, stri_detect_fixed, stri_detect_regex, stri_dup, stri_duplicated, stri_duplicated_any, stri_enc_detect, stri_enc_detect2, stri_enc_fromutf32, stri_enc_get, stri_enc_inf
Calls: coBC ... tryCatch -> tryCatchList -> tryCatchOne -> <Anonymous>
Execution halted